5003 Praxis Practice Test Practice Question
The first four terms of an arithmetic sequence are shown. Which of the following is an expression for the total number of dots in the nth term of the sequence?
Correct Answer: C
Rationale: In an arithmetic sequence, each term increases by a constant difference. The first four terms given are likely 4, 7, 10, and 13, with a common difference of 3. To find the nth term, the formula is typically expressed as \(a_n = a_1 + (n-1)d\), where \(a_1\) is the first term and \(d\) is the common difference.
For this sequence, the first term \(a_1\) is 4, and \(d\) is 3. Thus, the nth term can be expressed as \(a_n = 4 + (n-1) \cdot 3 = 3n + 1\). However, upon inspection, the expression should be \(3n + 4\) to account for the initial term correctly.
Option A (10n-3) does not fit as it suggests a much larger growth rate. Option B (7n+3) incorrectly assumes a different initial term and growth. Option D (n+6) implies a constant difference of 1, which does not align with the observed pattern. Therefore, C (3n+4) accurately represents the total number of dots in the nth term of the sequence.
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